Transmission spins while towing with transfer case in neutral

[Islandboy1220]

Odd, sounds like the screw up might very well be In Fords procedure because as you said in anything else you put the transmission in park while flat towing.

Correct. Everything else I looked at has you put the transmission in Park (or a gear if it is a stick shift). Even the GM 10 speed transmission gets put in park and GM/Ford developed the tranny together.

 

[fastpakr]

So... Put it in park to confirm the case is in neutral, then shift back to neutral?

 

[Dirtman]

So... Put it in park to confirm the case is in neutral, then shift back to neutral?

I may be wrong since I don't own one of these things but according to the official ford video I just watched about how it works, you can't do that. You can't put the Tcase in neutral until the transmission is in neutral and putting the transmission back into park turns off flat tow mode aka shifts transfer case back to 2wd.

https://owner.ford.com/support/how-tos/exterior/trailers-towing-loading/how-to-flat-tow-your-ford-ranger-or-raptor.html

 

[Islandboy1220]

Well the trans in Neutral would be a "safety" feature more than a requirement which is why Ford has that, IMO

Replacing the transmission if transfer case should come out of Neutral would be the lesser of 2 evils than if trans was in Park and 2(2 high) or 4(4 high) wheels suddenly locked up while towing, that could even break the vehicle away from tow vehicle, and who knows where that would lead, for other vehicles or people near where it happened
Park gear on trans would still be FUBARed and most likely trans itself
So Trans in Neutral is just safer, and a way lesser down side than Park

I agree. What I see wrong is that the Ford procedure does not have me mechanically confirm the TC is in neutral. If they would direct me to shift to D or R and watch for any movement (there should be none), I would be much happier. I am not even sure that part of it caused the problem, but I am frustrated because they have not given me a way to positively verify it.

 

[RonD]

Only verifications are external in any case
Transfer case shift motor has position sensor NOT the transfer case itself
And DTR sensor on outside of trans is the "neutral" sensor, nothing inside trans

Shifting to Park while hooked to RV wouldn't tell you much unless you tried to moved the RV, so two person job
D might work but only because of Speedometer, if transfer case was in Neutral you wouldn't "feel it" engage but would see speedometer go up to 8mph or so, OSS sensor
If you "feel it" engage then transfer case is not in Neutral

And none of this matters if transfer case is shifting out of neutral while towing
Which it is, in my opinion

 

[Islandboy1220]

Only verifications are external in any case
Transfer case shift motor has position sensor NOT the transfer case itself
And DTR sensor on outside of trans is the "neutral" sensor, nothing inside trans

Shifting to Park while hooked to RV wouldn't tell you much unless you tried to moved the RV, so two person job
D might work but only because of Speedometer, if transfer case was in Neutral you wouldn't "feel it" engage but would see speedometer go up to 8mph or so, OSS sensor
If you "feel it" engage then transfer case is not in Neutral

And none of this matters if transfer case is shifting out of neutral while towing
Which it is, in my opinion

Well, I am not in complete agreement with this statement. If the transmission is in park and the transfer case is in neutral, you can confirm the position of the transfer case by simply pulling the coach forward. If the wheels roll, it is a positive, physical verification the TC is in neutral.
If the TC is in neutral and you put the tranny in D or R, you should feel nothing. If anything moves or loads, the TC is not in neutral. This is exactly what Jeep instructs you to do for the Gladiator. And then they have you put it in park, so you can verify again by pulling forward.
Now, if the TC jumps out of neutral while towing, I think all bets are off on any toad.

 

[RonD]

Yes, thats what I said

 

[Islandboy1220]

Yes, thats what I said

Sorry. I read the ‘external verification’ comment differently. While anyone is on the outside of the transfer case, I see the rolling forward and put it in gear(s) as physical (internal) verification of the transfer case position.

 

[Islandboy1220]

Well, we are into the 6th week and I do have some additional information. Ford is standing behind their product, as I would expect, but it nice to have it confirmed. I suspect there was a communication issue between the dealer repairing it and Ford technical, but I think we have that corrected. Ford Technical is pointing to a possible low voltage to the transfer case that allowed the transfer case to shift out of neutral and spun the transmission until it failed. The voltage was indicated to be 10.8v or less. They recommended a charge line to maintain voltage.
That diagnosis is flawed because the truck started right up and there is a charge line already on it but as long as they fix the truck, I really don’t care. There could be a voltage (connection) problem between the battery and the TC, but it was clearly not the battery voltage that dropped. The other thing that does not make sense with that diagnosis is we saw the TC display say it shifted back out of neutral when we disconnected. It does not seem plausible to me that the TC would come out of neutral, spin the transmission to death and then go back into neutral.
I have approached the dealers and Ford about buying me out at a trade value so I can just move on and they are looking at that. I suspect it is just something really difficult to figure out with this specific truck. It will probably be fine to drive after it is repaired, but I really do not think the root cause is in that diagnosis.

 

[RonD]

Thanks for the update

Yes, that does sound like a stretch, especially since, as you observed, the transfer case still indicated Neutral, after damage had occurred, and did indicate a normal shift out of Neutral when vehicle was to be used again, and damage was discovered

I don't think a voltage issue would be root cause, the position indicator is not voltage dependent outside of the light being dimmer, lol
Not familiar with the new system but on the 2011 and earlier Fords the 4x4 controller did monitor transfer case position when it was powered up
i.e. you could turn off the key in 2WD and then put the selector switch in 4high, then turn on the key and 4x4 controller would shift to 4h when it was powered up again
And if you were to pull off the shift motor, key off 2WD, and then manually powered shift motor to say 4h or any position that wasn't 2WD, and then reconnected motor to harness and turned on the key, the 4x4 controller would move the motor so contacts were showing 2WD again

Now as far as I know the 4x4 controller on the newer Rangers wouldn't have power 24/7, no reason to, door open relay or on button would power it from what I have seen in the videos, so not sure how low voltage could effect it in the manner suggested


More likely the shift motor position indicator was in error, transfer case wasn't in Neutral at all, and because trans was in Neutral as well there would be no resistance in towing, which is why the shifting to Park thing would be better in my opinion, as that's a mechanical indicator that transfer case is in Neutral or NOT in Neutral

No, I don't think I would trust it again either, and 6 plus weeks downtime is unacceptable as well

 

[85_Ranger4x4]

If you turn one shaft of a gearbox in neutral it can still turn the other shaft at a much slower rate depending on the design of the box. Especially if one is turning fast, I could do that with my NP-205 on the bench without really trying too hard, spin the output and the input would spin slowly.

The oil between the uncoupled shafts I think has enough drag to spin the uncoupled shafts.

I always figured the "tow in park" thing was something related to that, with the transmission in park the chances of things basically windmilling and running dry are nil.

 

[Islandboy1220]

We did get an additional update. The transmission got damaged enough that they are replacing the transmission and cooling system. From what I was told, it means both metal and melted plastic were found in the system. We should get it back toward the end of next week, so that is good to have an end date in mind. It will also mean it took just about 7 full weeks. The timing was complicated by the dealer I purchased from not having full transmission capability. It waited in line to be looked at there and then at another dealer that is actually fixing it. I doubt we will ever know exactly what happened, but they confirmed the rotational forces that caused the transmission to heat up and self-distruct should have come from the TC engaging (or being engaged) when it was being towed. We know the screen said it (TC) was in the right place and that it also came back out and the transmission was in neutral. We also know the battery was fully charged, so I have to think something happened to drop electrical current from the TC, but no way to be sure.
Lots of people are towing these and systems like it and not having problems. We simply were unlucky. That being said, we are going ‘old school’ and switching to a Gladiator because they have a manual TC and are a favorite to tow behind a coach.
I truly appreciate the input and support received here! Thanks!!

 

[Islandboy1220]

Well, they tell me the Ranger is fixed and the dealer I bought it from will pick it up tomorrow and make me an offer for it. I will make a decision to either sell it to them or sell it myself based on their offer. I am simply spooked with flat towing this specific truck. They really cannot adequately explain what happened so if I have to change, I want a manual transfer case.
I did purchase a Gladiator Rubicon last week and am very happy with it. I am much more comfortable with the manual transfer case!

 

[Dirtman]

Just don't do this...

Jeep Wrangler Engine Explodes After Owner Tows Vehicle In Gear And Revs It To 50,000 RPM

A 2021 Jeep Wrangler’s 3.6-liter V6 engine apparently tried revving to eight times its redline after the owner left the vehicle’s transfer case in low-range while flat-towing, The Drive reports. The resulting stresses tore the engine apart, yielding a scene that looks as if it might have been...

jalopnik.com

 

[RonD]

Thanks for the update

To bad they can't define the reason it happened, or from what I have read, on why it happened on other Ford vehicles using the same flat-tow setup

I wouldn't trust it either